Breeding my female boxer

Question
My female boxer is either going before/during/or after her heat cycle. She has had a liter before but I don't remember her rear end being this swollen. My question is what phase of the cycle is she in or does this mean that she has already been bread by my male?

Answer
She will remain swollen throughout the heat cycle. A heat cycle is around 28-20 days.

The swelling sometimes subsides in the 3rd week, but not always.

Very soon after the vulva begins to swell, she will begin to produce a bloody discharge. The amount will vary from one girl to the next, so it may or may not be noticeable.

Sometime around nine to twelve days, the color of the discharge lightens to a pinkish-tan color, and it's usually around this time, referred to as estrus, that the vulva softens and eggs are released from the ovaries. At this point you may notice your girl flirting with other dogs; this is a sign she is ready to accept a male's advances.
Her tail will be cocked to one side and pointed up high to allow a male to mate. This is called "flagging."

If the heat cycle is allowed to continue uninterrupted, by the third week, the discharge begins to look bloody again. The amount will trail off until the cycle has concluded with anestrus.

Look for these signals that your girl is ready to be bred.

   * General flirty/affectionate behavior
   * Tail held high and flagging
   * Pushing up rear when petted on the back
   * Willingness to stand and present vulva
   * Color change in discharge from red to pinkish-tan